Ventilation system for inflatable pressure garments

ABSTRACT

An improved ventilation system for a space suit or other inflatable pressure garment assembly, such as used by astronauts and by pilots of high altitude vehicles operating in an environment having low oxygen content and low atmospheric pressures in which the life support gas enters at the helmet and exits through conduits leading from the extremities of both the arms and legs after passing in contact with the entire body of the wearer.

1451 June 6, 1972 United States Patent Durney s4] VENTILATION SYSTEM FOR 3,229,681 1/1966 Gluckstein........... ...12s 142.4 x INFLATABLE PRESSURE GARMENTS 3,291,126 12/1966 Messick...... ...128/142.5 [72] Inventor: 128/1427 X Shepard..........................

,293,6 9 12 1966 George P. Durney, Dover, Del. 3 5 l [73] Assignee: ILC Industries, Inc., Dover, Del. 7 Primary ExaminerRichard C. Pinkham [22] Filed: y 8, 1967 Assistant Exammer-Paul E. Shapiro Attorney-H. Gordon Dyke and Michael A. Sileo, Jr.

[21] App1.No.:

128/1415, 128/1427, 128/145 An improved ventilation system for a space suit or other in- 7/ 1 A62b 18/04 flatable pressure garment assembly, such as used by astronauts 128/142 and by pilots of high altitude vehicles operating in an environ- 128/145 ment having low oxygen content and low atmospheric pressures in which the life support gas enters at the helmet and [52] US. [51] Int. [58] Field [56] References Cited exits through conduits leading from the extremities of both the UNITED STATES PATENTS arms and legs after passing in contact with the entire body of the wearer.

w r u .W F g n m m 2 1 M C 0 1 .3 22 44 11 l/ 88 22 1.1

Akerman 2,861,568 11/1958 Quiltereta1........................

PATENTED H 8 I912 SHEET 10F 4 H M iii:

- l N VEN TOR QEORGE P Du/m/EY ATTOREY PATENTEBJUX 6 I972 3 667. 459

- SHEET 2 0F 4 INVENTOR GEORGE P. DUR/VEY ATTORNEY :mmw s we saw 3 0F 4 INVENTOR G EORGE R DUE/V5) ATTORNEY VENTILATION SYSTEM FOR INFLATABLE PRESSURE GARMENTS The invention described herein was made in the perfonnance of work under a NASA contract and is subject to the provisions of section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457).

This invention is an improved ventilation system for a pressure'garment assembly, (referred hereinafter as a fPGA).

My invention provides maximum availability of life support gas (which may be a mixture of gases) to the users head, and gives the PGA helmet improved purging of carbon dioxide and defogging of the visor. It also gives increased contact of the cool, dry, life support gas with the users arms, legs and torso, thus achieving improved moisture evaporation and body coolmg. a

In PGAs such as this invention is applied to, the life support gas enters the PGA at an inlet and leaves at an exit (usually being recirculated by a pump in a continuous closed system). In my invention the inlet is located in the helmet of the PGA, preferably combined with a diffuser located there, and exits at four exhaust points located at the extremities of the arms and legs of the PGA. Some of the intake gas after passing through the helmet flows over the arms and then exits, and some flows over the torso and along the legs and then exits; a lesser portion of the gas therefore flows proportionally over the arms (e.g. lpercent each) while the rest flows over the torso (e.g. 70percent) and then proportionally over the legs (e.g. 35percent each). The exits or outlets, which preferably are located in the gloves and boots of the PGA, remove the exhaust gas from the system and maintain uniform and continuous gas flow.

In a preferred embodiment of my ventilation system I provide, inter alia; intake and exhaust connectors which respectively couple and remove life support gas to and from the PGA; a gas distributing duct extending between the intake connector and the helmet; and gas removing ducts respectively extending between the exhaust connector and the extremities of the arm and leg sections of the PGA. By this construction substantially all the life support gas supplied to the PGA is delivered to the helmet and passes over the users head with approximately 30percent of the gas then proportionally flowing through the arms to the gas removing ducts located in the gloves of the PGA. The remaining portion of gas flows through the torso section of the PGA and then proportionally flows through the legs to the gas removing ducts located in the boots of the PGA. Maximum distribution of life support gas to the wearer's head is thus achieved for improved purging of carbon dioxide and visor defogging in the PGA helmet. Increased contact of life support gas with the users arms, torso and legs is also achieved for improved moisture evaporation and body cooling.

These and other features, objects and advantages of this invention will be apparent from the following description, reference being made to the accompanying drawings in which like reference numerals are utilized to designate like parts throughout, it being understood that such description and drawings are illustrative and not limitive of the invention.

FIG. 1 is a schematic view of the ventilation system of the present invention with the space suit and helmet shown in phantom.

FIG. 2 is a perspective view of a preferred embodiment of a three channeled ventilation duct.

FIG. 3 is a cross-sectional view of the right arm exhaust duct taken along the line 3-3 of FIG. 1.

FIG. 4 is a cross-sectional view of the right leg exhaust duct taken along the line 4-4 of FIG. 1.

FIG. 5 is a front perspective view of a preferred embodiment of the helmet diffuser of FIG. 1 with sections cut-away to show the inner structure of the helmet intake ducts which are connected to the helmet difi'user.

FIGS. 6 and 7 are left and right side views respectively of the helmet diffuser of FIG. 5.

FIG. 8 is an enlarged view of a section of the helmet diffuser of FIG. 5 showing a gas deflector plate for diffusing the gas into the helmet.

FIG. 9 is a perspective view of a preferred embodiment of the glove exhaust tube, wrist connector and Y-shaped connector of FIG. 1 with sections cut away to show internal structure.

FIG. 10 is a cross-sectional view of the glove exhaust tube taken along the line 10-10 of FIG. 9.

FIG. 11 is a perspective view of a preferred embodiment of the boot exhaust pad of FIG. 1 with sections cut-away to show the internal channel structure.

FIG. 12 is a cross-sectional view of the intake and exhaust plenums taken along the lines 12-12 of FIG. 1.

Referring first to FIG. 1, the space suit 10 and helmet 12 in which my invention is utilized, may be of any well known construction, such not being the subject of this invention, and as they are conventional they are merely indicated here with phantom lines.

The ventilation system of my invention comprises a pair of intake connectors 14,16; a pair of exhaust connectors 18,20; intake and exhaust plenums 22,24; a plenum connector 23; a pair of torso intake ducts 26,28; a pair of helmet intake ducts 30,32; a pair of arm exhaust ducts 34,36; a pair of leg exhaust ducts 38,40; a helmet diffuser 42; a pair of Y-shaped ducts 44,46; a pair of wrist connectors 48,50; a pair of glove exhaust tubes 52,54; and a pair of boot exhaust pads 56,58.

Intake connectors 14,16 and exhaust connectors 18,20 are flange mounted in conventional manner to the material of the front torso section of the PGA. A detailed description and showing of these connectors is not included since they are not a part of my invention. Intake members 14,16 may be any well known single-inlet, triple-outlet connector having a three way selective outlet manifold; while exhaust connectors 18,20 may be any well known triple inlet, single-outlet connector having a three way selective inlet manifold. Such connectors are commercially available from Air-Lock, Inc. of Milford, Connecticut, and are identified as Connector Assembly No. 9178.

Connector members 14,16,18 and 20 are structurally identical. Functionally, such members are intake members when life-support gas is delivered to its inlet port, and exhaust members when exhaust gas is removed from its outlet port.

In the preferred embodiment of FIG. 1 the upper connectors 14,16 are functionally intake connectors. Only one of them is used at a time, the other being used, for example, when the wearer changes from one life support system to another, or when it is desired to connect a second PGA in series through a buddy" system jumper duct.

One outlet of each of the intake connectors 14,16 is connected to the intake plenum 22; while the other two outlets are respectively connected to the torso intake ducts 26,28 and helmet intake ducts 30,32. Plenum 22 also functions to couple life-support gas from either intake connector to its opposite torso and helmet intake duct.

Functionally, lower connectors 18,20 are exhaust connectors, one only being used at a time with the other included for life-support change-over and buddy system purposes.

Exhaust connectors 18,20 each have three outlets, one from each being connected to the exhaust plenum 24; while the other two outlets are respectively connected to the arm exhaust ducts 34,36 and leg exhaust ducts 38 and 40. Plenum 24 also functions to couple exhaust gas from either arm or leg exhaust duct to its opposite exhaust connector.

Extending girthwise below each arm and along the side torso area of the PGA are the torso intake ducts 26,28, each terminating short of the rear-center of the torso. Ducts 26 ,28 distribute cool, dry, life-support gas to the middle torso area of the PGA.

The helmet intake ducts 30,32 extend upwardly from their respective intake connector, along the sides of the bottom edge of helmet 12, terminating at and connecting to the helmet diffuser 42. These ducts carry cool, dry, life-support gas to the diffuser which in turn distributes and directs the gas into the helmet 12.

Below and co-extensive with the torso intake ducts 26,28 are the arm exhaust ducts 34,36. They extend girthwise below ducts 26,28, sweeping upwardly in a smooth curve across the back section of the PGA, along its shoulder areas and then downwardly along the outer arm sections, respectively terminating at the wrist areas of the PGA. The Y-shaped ducts 44,46 respectively connect the arm exhaust ducts 34,36 to the wrist connectors 48,50. Extending from approximately the knuckle area of each PGA glove to its corresponding wrist connector 48,50 are glove exhaust tubes 52,54.

This completes the arm exhaust gas paths from the gloves of the PGA to the exhaust connectors 18,20.

Extending downwardly and rearwardly from the exhaust connectors 18,20 are leg exhaust ducts 38,40. These ducts extend along the outer leg sections, respectively terminating at the upper ankle areas of the PGA. The terminal ends of the leg exhaust ducts 38,40 are respectively connected to the boot exhaust pads 56,58, which extend downwardly across the outer ankle area, inwardly across the arches of the wearer and upwardly along the inner ankle area, terminating at the upperouter ankle area. Preferably, pads 54,56 have a lower-front portion that extends along the bottom foot area of the PGA.

This completes the leg exhaust gas paths from the boots of the PGA to the exhaust connectors 18,20.

This ventilation system has three primary intake modes of operation. The life support gas supplied to the PGA may be delivered (1) only to the torso intake ducts 26,28, (2) only to the helmet diffuser 42 via the helmet intake ducts 30,32, or (3) proportionally by both the helmet diffuser and torso intake ducts.

Selection of either one of these intake modes of operation is done by selectively directing all or part of the life-support gas to the outlets of the intake connectors 14,16, which are respectively connected to the torso intake ducts 26,28 and helmet intake ducts 30,32. Intake mode selectivity is provided by the above mentioned single-inlet, triple-outlet connector. For life-support change-over and buddy system purposes it is preferable that the outlets of the intake connectors 14,16, which are connected to the intake plenum 22, are always open during each intake mode of operation. This feature also provides balanced gas distribution to the system and a uniform pressure profile.

There are three primary exhaust modes of operation. The life support gas may be exhausted (1) only by the glove exhaust tubes 50,52, (2) only by the boot exhaust pads 54,56, or 3) by both the glove tubes and boot pads.

Selection of either one of these exhaust modes of operation is done by selectively connecting the inlets of the exhaust connectors 18,20 to the arm exhaust ducts 34,36 and leg exhaust ducts 38,40. Exhaust mode selectivity is provided by the above mentioned single-outlet, triple-inlet connector, and lifesupport change-over and buddy" system capability is provided by keeping the exhaust plenum inlets of the connectors 18,20 open during each exhaust mode of operation.

In FIG. 1 the unfilled-in" arrows represent gas flow direction of the life-support gas while the "filled-in" arrows represent gas flow direction and paths of the exhaust gases.

The function of the cool, dry gases distributed by the torso intake ducts 26,28 and helmet diffuser 42 are three fold. First they remove moisture from the PGA and cool the users body; second they purge the PGA, particularly in the helmet section, of carbon dioxide exhaled by the user; and third they defog the face plate of the PGA helmet.

Continuous and uniform gas flow through the PGA is maintained by keeping the pressure at the lower ends of the arms and legs lower than the pressure value of the life support gas delivered to the system. In the embodiment shown and described here this is achieved by connecting life-support gas to the intake connectors 14,16 that has a higher pressure than the pressure value at the exhaust connectors 18,20.

The pressure differential (AP) between intake (P,) and exhaust (P may be computed as follows:

l. Determine the quantity of gas necessary to adequately ventilate and purge the space suit in which this ventilation system is to be used, with minimum-user-comfort" as a guide, this quantity may be either in lbs/hr. or CFM/min depending, for convenience, on whether absolute pressure is a variable;

2. Compute the difierential pressure (AP required to compensate for pressure losses in each of the suit and system components (AP APg; AP etc.).

A first approximation of a formula for the required pressure difference (AP between intake (P and exhaust (P would be Reference is now made to FIGS. 2-4 which respectively show: (1) a perspective view of the arm exhaust duct 34, which is a three coil gas duct; (2) a cross-sectional view of the arm exhaust duct 34; and (3) a cross-sectional view of the leg exhaust duct 38, which is a four coil gas duct. The elements in FIGS. 3 and 4 are slightly separated from each other for graphic representation simplification.

To significantly reduce pressure losses in the ventilation system of any PGA, substantially constant volume or noncrushable gas carrying ducts should be used. FIGS. 2-4 show preferred embodiments of ducts having substantially constant volume or non-crushable characteristics. A more detailed description of non-crushable conduits may be found in a copending patent application Ser. No. 782,283, filed Dec. 9, 1969, which is assigned to the assignee of this patent application.

The arm exhaust duct 34 of FIGS. 2 and 3 comprises coil members 60,62,64, inner covers 66,68 and outer covers 70,72. The coils 60,62,64 are made of hard material, such as wire or plastic, and have spaced parallel axes. Surrounding the coils and holding them in relative position are the inner covers 66,68, such being connected together by two rows of longitudinal stitching 74,76. Positioned about the inner covers 66,68 are the outer covers 70,72, such being secured at their areas of overlap by adhesive 78. Gas duct 34 is connected to the PGA 10 by adhesive 80.

Inner covers 66,68 need not be impermeable to the gas passing through the duct, but outer covers 70,72 must be substantially impermeable to such gas so that the gas, if desired, may be coupled to the helmet section of the PGA with a minimum of gas leakage. Preferably, inner covers 66,68 are made from nylon mesh fabric, while the outer covers 70,72 are made from a sheet of rubber impregnated nylon fabric.

It is to be understood that inner covers 66,68 and outer covers 70,72 may be sleeves rather than the preferred two piece construction shown and described. The longitudinal stitchings 74,76, however are still used to hold and separate the coils whether the two piece construction or the sleeve construction is used.

The two piece inner and outer cover construction is desirable because it (1) simplifies fabrication techniques, (2) allows production line compensation for slight variations in material dimensions and stitch characteristics, and (3) permits more accurate inspection of materials during fabrication.

Since the four coil, leg exhaust duct 38 of FIG. 4 is structurally similar in many respects to the three coil arm exhaust duct 34 of FIG. 3, like elements thereof are referenced with numerals identical to their corresponding elements in the three coil duct 34.

The primary difierences between the ducts 34 and 38 are (l) the addition of coil 65, (2) the inner covers 66 and 68 are wider to compensate for the extra coil 65, and (3) the exhaust duct 38 is secured to the PGA 10 by a fabric strip connector 79, which overlays the top and sides of the exhaust duct 38 and has its ends secured to the PGA 10 by adhesive 80.

It is contemplated that other well known techniques can be used to secure the intake and exhaust ducts of the system to the PGA, e.g., they can be stitched or heat sealed, without departing from the scope of this invention.

The above described three coil and four coil gas ducts are interchangeable in the system in that each may be used as intake or exhaust ducts. In the preferred embodiment of this invention the torso intake ducts 26,28, helmet intake ducts 30,32 and arm exhaust ducts 34,36 are three coil ducts, while the leg exhaust ducts 38,40 are four coil ducts.

Although the torso intake ducts 26,28 are substantially the same as the three coil ducts above described, they are also capable of uniformly diffusing intake gases to the torso section of the PGA when desired. This feature may be provided by making the outer covers 70,72 of the ducts gas permeable. One technique is to perforate the outer covers 70,72 in spaced intervals. Of course other well known techniques for providing this gas permeable feature may be used.

FIGS. 5-8 respectively show: l a front perspective view of the helmet diffuser 42 and the helmet intake ducts 30,32 with cut-away portions to show how the ducts are joined; (2) a left side view of the diffuser 42 showing the open end of the intake gas channel and the spaced diffuser plates; (3) a right side view of the diffuser 42 showing the closed end of the intake gas channel and the spaced diffuser plates; and (4) an enlarged view of a single diffuser plate with cut-away portions.

Diffuser 42 has an outer surface that conforms to and abuts the inner surface of the helmet section 12, and an inner surface that conforms to the rear of the head of the user. The lower end of the diffuser 42 is secured to the inner neck ring 82 of a conventional PGA neck ring connector. Secured to the inner neck ring 82 is outer neck ring 84, which is also secured to the PGA 10. The primary reason for neck rings 82,84 is to provide a detachable helmet feature. That is to say, neck rings 82,84 should be detachably secured to each other so that the helmet 12 can be disconnected and taken off when desired. Helmet disconnect structure is not shown or described here since it is not a part of my invention.

Formed in the helmet diffuser 42 is a channel 86 extending from the lower left edge, up the left side across the top and down the right side, terminating short of the lower right edge. Channel 86 forms a front ridge 88 and a rear surface 90.

At spaced intervals along the front ridge 88 are diffuser plates 92. Plates 92 are seated in spaced slots, as shown in FIG. 8, and are either held in position by friction or by an adhesive.

When diffuser 42 is secured to the helmet 12, rear surface 90 and the upper edges of diffuser plates 92 abut the inner surface of the helmet 12. By this construction (1) a primary airflow duct is formed in the helmet diffuser 42, as defined by the channel 86 andthe overlying area of the inner surface of the helmet 12, and (2) a plurality of adjacent outlets are provided from the air-flow duct, each defined by any two adjacent diffuser plates 92, the front ridge 88 and the overlying area of the inner surface of the helmet 12.

Intake ducts 30,32 are joined together and secured to the inner neck ring 82 for coupling intake gas to the helmet diffuser 42. A preferred construction for joining the intake ducts 30,32 is shown at the bottom of FIG. 5.

The lower coil of the intake ducts 30,32 are joined together, but the upper two coils of each intake duct are positioned in parallelism to form a four coil duct 94 as shown in FIG. 4. The upper end of duct 94 is connected to the inner neck ring 82 by a neck ring connector 96, which has a slot 98 formed therein. Neck ring connector slot 98 is directly below and corresponds to an inner neck ring slot 100, which in turn is directly below and corresponds to the channel 86 of the helmet diffuser 42.

Positioned below the upper coils of intake ducts 30,32 and above the joined lower coils is a triangular-shaped spacer 102. This spacer holds the upwardly bending upper coils of ducts 30,32 in the position shown. They may be made of relatively stiff air permeable material such as a nylon mesh corrugated fabric.

The intake gases are therefore coupled to the helmet 12 via helmet intake ducts 30,32, four coil duct 94, neck ring connector slot 98, inner neck ring slot 100, and channel 86. The above mentioned primary air-flow duct defined by channel 86 then couples the intake gas to each of the above mentioned adjacent outlets defined by the diffuser plates 88 which in turn uniformly distribute and diffuse the intake gas into the helmet 12.

It is to be understood at this point that other well known life-support gas distribution and diffusing techniques may be substituted without departing from the spirit and scope of this invention.

FIGS. 9 and 10 respectively show (I) a perspective view of a structure for removing exhaust gases from the glove sections of the PGA and coupling such gases to the arm exhaust duct 34, and (2) a cross-sectional view of the glove exhaust tube 52. In FIG. 9 parts of the arm exhaust duct 34, Y-connector 44, wrist ring 48 and glove exhaust tube 52 are cut away to show preferred internal structure. While in FIG. 10 the elements of the glove exhaust tube 10 are slightly separated from each other for graphic representation simplification.

Glove exhaust tube 52 extends from the upper knuckle area of the user to his wrist and includes spacer coils 104,106, corrugated spacer 108, inner cover 110, outer cover 112, and glove exhaust tube connector 114 (partially cut away). The longitudinal axis of spacer coils 104,106 and spacer 108 are preferably parallel with the spacer coils 104,106 being made of hard material, such as wire or plastic, and the spacer 108 being made of a nylon mesh fabric, corrugated as shown, and held in that position by upper and lower transverse stitches 117,118.

Surrounding the spacer coils 104,106 and spacer 108, and holding them in relative position is the inner cover 110, such being connected by stitches 116. Positioned around the inner cover 110 is outer cover 112, such being secured at its area of overlap by adhesive 120. The glove exhaust tube connector 114 secures one end of exhaust tube 52 to the wrist ring 48, while the other end of tube 52 is unsecured and free.

Inner cover 110 need not be impermeable to the gas passing through the exhaust tube, but the outer cover 112 must be gas impermeable so that all of the gases in the gloves of the PGA may be coupled to the wrist ring 48. Preferably, inner cover 1 10 is made from a nylon mesh fabric, while the outer cover is made from a sheet of rubber impregnated nylon fabric. To permit gas passage from the glove of the PGA to the glove exhaust tube, the free end thereof is constructed so as to be gas permeable. This may be achieved by terminating the outer cover 112 short of the end of the exhaust tube 52, as shown in FIG. 9, or by using a full outer cover perforated at the end to allow gas passage.

Glove exhaust tube 52 should be at least cursh resistant and need not be non-crushable as the intake and exhaust ducts above described because a greater degree of flexibility is desirable in the glove areas of the PGA. Accordingly, any well known exhaust member can be substituted so long as it has crush resistance characteristics yet is slightly flexible.

Wrist ring 48 includes upper and lower rims 120,122 connected together by inner and outer cylinders 123,124. A slot 126 is provided in the lower rim 122 while a corresponding slot 115 is provided in the glove exhaust tube connector 114. I-Ioles 128 are provided in the lower rim 122 for securing the glove exhaust tube connector 114 to it. By this construction, an unimpeded path for gas flow is provided from the glove exhaust tube 52, through the glove exhaust tube connector 114 and lower rim 124 to the space between the inner and outer cylinders 123,124.

The legs of Y-duct 44 are identical and respectively include spacer coils 60,62, and 61,64, inner covers 67,69, and outer covers 71,73. Although the legs of Y-duct 44 are shown with one piece inner and outer covers, it is to be understood that the two piece construction above described regarding the ducts of FIGS. 2 and 3 may be substituted.

Two identical Y-duct connectors 130 secure the legs of the Y-duct 44 to the upper rim 120, with each having a slot 131 formed therein. Upper rim has slots 129 formed therein which correspond to slots 131, and appropriate holes for securing the Y-duct connectors 130 to it. By this construction,

two unimpeded paths for gas flow are provided from the space between the inner and outer cylinders 123,124, through the upper rim 120 and connectors 130 to the legs of the Y-duct 44.

The tail of the Y-duct 44 includes spacer coils 60 and 64, which are the outside spacer coils of the arm exhaust duct 34, and inner spacer coil 62. Spacer coil 61 terminates slightly above the junction of the legs of the Y-duct, and is interdigitated with the inner spacer coil 62. Structurally, the tail of Y-duct 44 merges into the lower end of the arm exhaust duct 34.

The structure of FIGS. 9 and 10 shows a preferred, partially crush resistant, partially non-crushable, unimpeded path for exhaust gas flow from the PGA gloves to the arm exhaust ducts.

In FIG. 1 1, a perspective view of a preferred embodiment of the boot exhaust pad 56 of FIG. 1 is shown with sections cutaway to show preferred internal structure.

Boot exhaust pad 56 extends from the leg exhaust duct 38, along the outer ankle area, inwardly across the arches of the wearer and upwardly along the inner ankle area, terminating at the upper-outer ankle area. Pad 56 also has a lower-front portion that extends along the bottom foot area of the PGA.

The outer ankle section of the exhaust pad 56 comprises a corrugated spacer 132, made of a nylon mesh fabric and held in position by upper and lower transverse stitches 134,136, and a cover 138; while the inner ankle section of boot pad 56 comprises a corrugated spacer 133, also made of a nylon mesh fabric having upper and lower transverse stitches 135,137, and a cover 139. The bottom section of pad 56 is preferably two layers of corrugated spacers 142,143, which are identical to spacers 132,133, surrounded by cover 140.

The covers 138,139 and 140 are gas pervious, thus providing a path for gas flow from the boot area of the PGA to the leg exhaust duct 38. Spaced perforations in covers 138,139 and 140 adequately provide gas passage through the boot pad.

At the upper end of the outer ankle section of boot pad 56, the cover 138 is larger as shown at 141. This larger cover portion 141 allows the spacer coils 60,62,64,65 of the leg exhaust duct 38 to overlap the corrugated spacer 132 and connects the ends of the leg exhaust duct 38 to the boot pad 56.

Since the boot exhaust pad 58 is identical to boot pad 56, except that it is a mirror image of it, a detailed description thereof is not included.

The structure of FIG. 11 shows a preferred, crush resistant, unimpeded path for exhaust gas flow from the PGA boots to the leg exhaust ducts.

Referring now to FIG. 12, a cross-sectional view of the intake and exhaust plenums 22,24, and plenum connector 23 is shown. Since the intake and exhaust plenums are identical, like elements thereof have been referenced with the same material.

Each plenum comprises a plurality of coil spacers 144, inner covers 146,148, rubber bladder 152, and outer cover 154. Coils 144 are made of hard material, such as wire or plastic, and have spaced parallel axes. Surrounding the coils and holding them in relative position are the inner covers 146,148, such being connected together by longitudinal rows of stitches 150. Positioned about the inner covers 146,148 is the rubber bladder 152 which snugly abuts them. Tightly positioned about the bladder 152 is the outer cover 154. The plenums are held in relative position by the plenum connector 156, which has its ends secured together at this area of overlap by adhesive, 158, and are secured to the PGA 10 by adhesive 160.

While I have illustrated the presently preferred embodiment of my invention, it will be understood that its teachings, in whole or in part, can be incorporated in many variations.

What is claimed is:

1. A ventilation system for distributing life-support intake gas to and removing said gas as exhaust from an inflatable pressure garment assembly wherein:

I. said assembly has helmet, arms, legs and torso sections;

2. life-support gas intake and exhaust connector means are positioned in said torso section for conveying said intake gas to and said gas as exhaust from said assembly;

3. intake duct means extend between said intake connector means and said helmet section for distributing said intake gas into said helmet section, for purging said helmet section of carbon dioxide;

4. a first pair of exhaust gas conveying duct means coupled to said torso exhaust connector means extending between the lower arm sections and said exhaust connector means for conveying the gas as exhaust in said lower arm sections to said exhaust connector;

5. a second pair of exhaust gas conveying duct means coupled to said torso exhaust connector means extending between the lower leg sections and said exhaust connector means for conveying the gas to be exhausted in said lower leg sections to said exhaust connector means; and

6. the pressure in the lower arm and leg sections of said assembly is relatively lower than the pressure value of said intake gas so as to cause a small portion of said intake gas to proportionally flow through said arm sections to said first pair of gas exhaust duct means, and to cause the remaining larger portion of said intake gas first to flow through said torso section and then proportionally through said leg sections to said second pair of exhaust gas conveying duct means, thus providing increased contact of said intake gas with the users body for moisture evaporation and body cooling.

2. The ventilation system of claim 1 in which said life-support gas intake connector means fiirther includes at least one torso intake duct located in said torso area for diffusing at least a portion of said life-support gas in the area of said torso portion of said assembly, said torso duct having one end connected to said intake connector and its other end terminating in the torso area remote from said intake connector.

3. The ventilation system of claim 1 in which said intake connector is adjustable so that any one or more of said helmet and torso intake duct means may be used to distribute life-support gas to said assembly.

4. The ventilation system of claim 1 in which said exhaust connector means has adjustable means therein so that any one or more of said exhaust ducts may be used to remove exhaust gas from said assembly.

5. The ventilation system of claim 1 in which each of said exhaust means located at the ends of said arm sections has an exhaust tube connected to its open end, said exhaust tubes being respectively located in the hand sections of the assembly, terminating at the knuckle area thereof, and each has spaced openings through which said gas, as exhaust, passes and is coupled to said arm exhaust ducts.

6. The ventilation system of claim 1 in which each of said exhaust duct means located at the ends of said leg sections has an exhaust pad connected to its open end, said exhaust pads conforming to the outer surfaces of the users ankles and bottom surface of the users feet and each has spaced openings through which said gas as exhaust passes and is coupled to said leg exhaust duct means.

7. The ventilation system of claim 1 in which said life-support gas intake connector means includes at least one helmet intake duct having one end connected to a life-support gas intake connector and its other end connected to a helmet diffuser pad connected to the rear area of said helmet section, said helmet intake ducts conveying said life-support gas from said intake connector to said pad, and said pad diffusing said life-support gas against the users head and against the front area of said helmet section so as to purge said helmet section of carbon dioxide and defog said front section.

8. A ventilation system for distributing life-support intake gas to and removing exhaust gas from an inflatable pressure garment assembly wherein:

1. said assembly has helmet, arms, legs and torso sections;

2. life-support gas intake and exhaust connectors are positioned in said torso section for respectively conveying said life-support intake gas to and said exhaust gas from said assembly;

3. a pair of life-support gas intake ducts respectively extend between said intake connector and said helmet section for distributing said intake gas into said helmet section, for purging said helmet of carbon dioxide and for defogging said helmet;

4. a first pair of exhaust gas conveying ducts coupled to said torso exhaust connector respectively one each extending between the lower arm sections and said exhaust connector for conveying the gas as exhaust in said lower arm sectionsto said exhaust connector;

5. a second pair of exhaust gas conveying ducts coupled to said torso exhaust connector respectively extend between the lower leg sections and said exhaust connector for conveying the gas as exhaust in said lower leg sections to said exhaust connector; and

6. the pressure in the lower arm and leg sections of said assembly is relatively lower than the pressure value of said intake gas so as to cause a small portion of said intake gas to proportionally flow through said arm sections to said first pair of gas exhaust ducts, and to cause the remaining larger portion of said intake gas first to flow through said torso section and then proportionally through said leg sections to said second pair of exhaust gas conveying ducts, thus providing increased contact of said intake gas with the users body for moisture evaporation and body cooling.

9. The ventilation system of claim 8 and further including a pair of torso intake ducts respectively extending from said intake connector around the area of said torso portion of said assembly to the rear section of the garment diffusing a portion of said intake gas against the users torso in said torso area.

10. The ventilation system of claim 9 in which:

1. said intake connector is adjustable so that any one or more of said intake ducts may be used to distribute intake gas to said assembly; and

2. said exhaust connector is adjustable so that any one or more of said exhaust ducts may be used to remove exhaust gas from said assembly. 

1. A ventilation system for distributing life-support intake gas to and removing said gas as exhaust from an inflatable pressure garment assembly wherein:
 1. said assembly has helmet, arms, legs and torso sections;
 2. life-support gas intake and exhaust connector means are positioned in said torso section for conveying said intake gas to and said gas as exhaust from said assembly;
 3. intake duct means extend between said intake connector means and said helmet section for distributing said intake gas into said helmet section, for purging said helmet section of carbon dioxide;
 4. a first pair of exhaust gas conveying duct means coupled to said torso exhaust connector means extending between the lower arm sections and said exhaust connector means for conveying the gas as exhaust in said lower arm sections to said exhaust connector;
 5. a second pair of exhaust gas conveying duct means coupled to said torso exhaust connector means extending between the lower leg sections and said exhaust connector means for conveying the gas to be exhausted in said lower leg sections to said exhaust connector means; and
 6. the pressure in the lower arm and leg sections of said assembly is relatively lower than the pressure value of said intake gas so as to cause a small portion of said intake gas to proportionally flow through said arm sections to said first pair of gas exhaust duct means, and to cause the remaining larger portion of said intake gas first to flow through said torso section and then proportionally through said leg sections to said second pair of exhaust gas conveyiNg duct means, thus providing increased contact of said intake gas with the user'' s body for moisture evaporation and body cooling.
 2. life-support gas intake and exhaust connector means are positioned in said torso section for conveying said intake gas to and said gas as exhaust from said assembly;
 2. The ventilation system of claim 1 in which said life-support gas intake connector means further includes at least one torso intake duct located in said torso area for diffusing at least a portion of said life-support gas in the area of said torso portion of said assembly, said torso duct having one end connected to said intake connector and its other end terminating in the torso area remote from said intake connector.
 2. life-support gas intake and exhaust connectors are positioned in said torso section for respectively conveying said life-support intake gas to and said exhaust gas from said assembly;
 2. said exhaust connector is adjustable so that any one or more of said exhaust ducts may be used to remove exhaust gas from said assembly.
 3. a pair of life-support gas intake ducts respectively extend between said intake connector and said helmet section for distributing said intake gas into said helmet section, for purging said helmet of carbon dioxide and for defogging said helmet;
 3. The ventilation system of claim 1 in which said intake connector is adjustable so that any one or more of said helmet and torso intake duct means may be used to distribute life-support gas to said assembly.
 3. intake duct means extend between said intake connector means and said helmet section for distributing said intake gas into said helmet section, for purging said helmet section of carbon dioxide;
 4. a first pair of exhaust gas conveying duct means coupled to said torso exhaust connector means extending between the lower arm sections and said exhaust connector means for conveying the gas as exhaust in said lower arm sections to said exhaust connector;
 4. The ventilation system of claim 1 in which said exhaust connector means has adjustable means therein so that any one or more of said exhaust ducts may be used to remove exhaust gas from said assembly.
 4. a first pair of exhaust gas conveying ducts coupled to said torso exhaust connector respectively one each extending between the lower arm sections and said exhaust connector for conveying the gas as exhaust in said lower arm sections to said exhaust connector;
 5. a second pair of exhaust gas conveying ducts coupled to said torso exhaust connector respectively extend between the lower leg sections and said exhaust connector for conveying the gas as exhaust in said lower leg sections to said exhaust connector; and
 5. The ventilation system of claim 1 in which each of said exhaust means located at the ends of said arm sections has an exhaust tube connected to its open end, said exhaust tubes being respectively located in the hand sections of the assembly, terminating at the knuckle area thereof, and each has spaced openings through which said gas, as exhaust, passes and is coupled to said arm exhaust ducts.
 5. a second pair of exhaust gas conveying duct means coupled to said torso exhaust connector means extending between the lower leg sections and said exhaust connector means for conveying the gas to be exhausted in said lower leg sections to said exhaust connector means; and
 6. the pressure in the lower arm and leg sections of said assembly is relatively lower than the pressure value of said intake gas so as to cause a small portion of said intake gas to proportionally flow through said arm sections to said first pair of gas exhaust duct means, and to cause the remaining larger portion of said intake gas first to flow through said torso section and then proportionally through said leg sections to said second pair of exhaust gas conveyiNg duct means, thus providing increased contact of said intake gas with the user'' s body for moisture evaporation and body cooling.
 6. The ventilation system of claim 1 in which each of said exhaust duct means located at the ends of said leg sections has an exhaust pad connected to its open end, said exhaust pads conforming to the outer surfaces of the user''s ankles and bottom surface of the user''s feet and each has spaced openings through which said gas as exhaust passes and is coupled to said leg exhaust duct means.
 6. the pressure in the lower arm and leg sections of said assembly is relatively lower than the pressure value of said intake gas so as to cause a small portion of said intake gas to proportionally flow through said arm sections to said first pair of gas exhaust ducts, and to cause the remaining larger portion of said intake gas first to flow through said torso section and then proportionally through said leg sectioNs to said second pair of exhaust gas conveying ducts, thus providing increased contact of said intake gas with the user'' s body for moisture evaporation and body cooling.
 7. The ventilation system of claim 1 in which said life-support gas intake connector means includes at least one helmet intake duct having one end connected to a life-support gas intake connector and its other end connected to a helmet diffuser pad connected to the rear area of said helmet section, said helmet intake ducts conveying said life-support gas from said intake connector to said pad, and said pad diffusing said life-support gas against the user''s head and against the front area of said helmet section so as to purge said helmet section of carbon dioxide and defog said front section.
 8. A ventilation system for distributing life-support intake gas to and removing exhaust gas from an inflatable pressure garment assembly wherein:
 9. The ventilation system of claim 8 and further including a pair of torso intake ducts respectively extending from said intake connector around the area of said torso portion of said assembly to the rear section of the garment diffusing a portion of said intake gas against the user'' s torso in said torso area.
 10. The ventilation system of claim 9 in which: 